Abstract: An automatic switching mechanism for a model plane starter motor having a clutch bushing for gripping the propeller spinner of the plane includes a base member, a movable member movably mounted to the base member, means for mounting a starter motor to the movable member; means for biasing the movable member to a first position; and switch means for closing the electrical power circuit through the starter motor as the movable member approaches a second position responsive to the engagement of the airplane propeller spinner with the starter motor clutch bushing.